Presently, when air bag covers are provided in automobiles on the driver's side of the vehicle, the air bag is stored in the steering column behind an air bag cover. During automatic inflation of the air bag, the air bag cover moves away from the steering column to permit its safety function between the steering column and the operator of the vehicle.
Recent practice in the automotive industry is utilization of all plastic fabricated air bag covers. It is known in other automotive parts areas that different, aesthetically pleasing outer surfaces enhance the overall appearance of the interior of automotive vehicles. Use of decorative appliques having solid colors contrasting or blending with the different colors of the plastic air bag covers is often sought after. Simulated wood grain finishes, and metallic finishes are also popular and economically feasible in combination with various plastic automotive parts.
Difficulties are known to arise in properly applying applique films to annular or arcuate plastic outer surfaces. Applique films are usually approximately 0.5 millimeters thick or less and are therefore not easily applied directly to an outer air bag cover surface. Improper application causes small air pockets to occur on the decorative film which often makes the resultant air bag cover, unattractive and thus unusable. Additionally, conventional air bag covers invariably include annular or arcuate surfaces, and affixing the thin applique film to these designated surfaces is even more difficult.
The deposition or fastening of the applique must be perfected with a method that affords a smooth surface and neat appearance. Thus it is known to utilize a backing material or liner in conjunction with a thin applique film to afford a clean, smooth appearance of the final product.
In addition, the applique must be affixed to the front cover in such a way as to prevent the applique from separating from the front cover when the air bag explodes. The applique must therefor be bonded to the front cover with sufficient strength to prevent fragmentation of the applique during air bag inflation and exit.